import java.util.PriorityQueue;
import java.util.Timer;
import java.util.TimerTask;

//1.任务类
class MyTimerTask implements Comparable<MyTimerTask>{
    //Runnable是接口
    private Runnable task;
    private long time;

    public MyTimerTask(Runnable task, long time){
        this.task = task;
        this.time = time;
    }

    @Override
    public int compareTo(MyTimerTask o) {
        return (int)(this.time - o.time);
    }

    public long getTime(){
        return time;
    }

    public void run(){
        task.run();
    }
}


class MyTimer{

    //2。采用阻塞队列处理任务
    private PriorityQueue<MyTimerTask> queue = new PriorityQueue<>();

    private Object locker = new Object();

    //3.创建schedule方法
    public void schedule(Runnable task, long delay){
        synchronized(locker){
            MyTimerTask timerTask = new MyTimerTask(task, System.currentTimeMillis() + delay);
            queue.offer(timerTask);
            locker.notify();
        }
    }

    public MyTimer(){
        Thread t = new Thread(() -> {
            try{
                while(true){
                    synchronized(locker){
                        while(queue.isEmpty()){
                            locker.wait();
                        }
                        MyTimerTask task = queue.peek();
                        if(System.currentTimeMillis() < task.getTime()){
                            locker.wait(task.getTime() - System.currentTimeMillis());
                        }else{
                            task.run();
                            queue.poll();
                        }
                    }
                }
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        });

        t.start();
    }
}


public class demo2{
    public static void main(String[] args) {
        MyTimer timer = new MyTimer();
        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                System.out.println("hello 3000");
            }
        }, 3000);

        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                System.out.println("hello 2000");
            }
        }, 2000);

        timer.schedule(new TimerTask() {
            @Override
            public void run() {
                System.out.println("hello 1000");
            }
        }, 1000);

        System.out.println("hello main");
    }
}